My cats consider me their heating pad. When I lay down on the couch to watch TV, Spike balances on my shoulder/side and makes himself comfortable. When I get into bed for the night, Spike assumes that same position, and Kirby spreads herself atop my feet (Zoey sleeps in the kitty bed nearby). That can't possibly be comfortable for Kirby, but she does it most nights.
I wonder all the time how often I kick my cat in my sleep.